Advising national climate policy makers: A longitudinal analysis of the UK Climate Change Committee     

《Global Environmental Change》2022

Despite the recent proliferation of national climate change advisory bodies, very little is known about what advice they provide, to whom, and when. To address these gaps in the literature, this article systematically analyses all 700 of the recommendations made by the UK Climate Change Committee (CCC) in the period 2009–20. The CCC is one of the oldest climate change advisory bodies of its kind in the world and its design has been widely emulated by other countries. For the first time, this article documents how the CCC’s mitigation and adaptation recommendations have changed over time with respect to their addressee, sectoral focus and policy targets. It reveals that they became: more numerous per year; more cross-sectoral in their nature; clearer in targeting a specific addressee; and more focused in referring to specific policy targets. By drawing on Fischer’s synthesis of policy evaluation to derive a measure of policy ambition, it also reveals that despite many of its recommendations being repeated year after year, the CCC has become more willing to challenge the policy status quo. It concludes by identifying future research needs in this important and fast-moving area of climate governance, notably understanding the conditions in which the recommendations of advisory bodies (do not) impact national policy.  相似文献   

沿江丘陵平原工程地质分区研究——以安庆地区为例     

郭炳跃  王毅  戴俊成 《江苏地质》2021,45(3):327-334

长江中下游地区沿江丘陵平原地貌分布广泛且地质背景相似,开展单个地区的工程地质分区方法研究,对同类区域具有一定的借鉴意义。以安庆地区为例,提出一级分区以地貌类型,二级分区以岩土体类型、结构和重要工程地质层分布为划分原则的工程地质分区方法,将该区划分为5个工程地质区和14个工程地质亚区,并对各分区工程地质特性进行论述,旨在为同类区域水工环地质调查、城市地质调查研究提供参考。  相似文献   

淮北隐伏岩体的地球化学特征、岩石成因及构造意义     

于炎炎 《江苏地质》2021,45(4):384-390

通过对淮北隐伏岩体的岩相学、地球化学特征的研究,揭露了岩体的岩石成因、源区性质及构造环境。采集了6件化学分析样品用于主微量与稀土元素分析,6件岩矿鉴定标本用于镜下薄片分析。显微镜下特征显示,岩体岩性为石英二长闪长玢岩和石英角闪闪长玢岩。主量元素特征显示,岩体具富SiO2（60.70%～68.28%）、富Na2O（3.81%～6.22%）、富Al2O3（14.07%～15.12%）的特征,且Mg#值（43.75～61.25）较高,属准铝质高钾钙碱性岩石。稀土元素特征显示,岩体轻重稀土分馏明显,表现为轻稀土富集、重稀土亏损,无明显Eu异常（δEu平均值=0.95）和Ce异常（δCe平均值=0.92）。微量元素特征显示,岩体具高Sr（563～868 g/t）、低Y（379～114 g/t）、高Sr/Y比、低Yb（0.50～1.26 g/t）的特征,Rb/Sr比值较低（0.07～0.11）。综合研究表明,淮北隐伏岩体为具埃达克岩性质的岩石,形成于加厚下地壳发生拆沉的环境下,下地壳深部的石榴辉石岩相部分熔融产生岩浆,与地幔橄榄岩发生反应,在岩浆移出源区后,经历了不同程度的分离结晶,形成了石英二长闪长玢岩与石英角闪闪长玢岩。  相似文献   

甘肃玛曲格尔托金矿床矿区地质及主矿体特征          下载免费PDF全文

梁硕鹏  陈耀宇  李林积  李昊鹏  冯兰君 《甘肃地质》2021,(1):49-56

新探明的格尔托中型金矿床,与格尔珂、贡北金矿床构成了大水金矿田。本文从地层、构造、岩浆岩、围岩蚀变等方面总结了格尔托金矿床的矿区地质特征,又从主矿体规模、厚度稳定程度、品位分布均匀程度、形态产状、资源量占比等方面总结了格尔托金矿床的主矿体特征,进而简要对比分析了大水金矿田各矿床的矿区地质特征和主矿体的资源量占比及分布特征。  相似文献   

甘肃金川早古生代正长花岗岩锆石SHRIMP U-Pb年代学、岩石学、地球化学特征及其构造意义     

张晓旭  苏尚国  刘美玉  王为柱 《地学前缘》2021,28(4):283-298

报道了甘肃金川正长花岗岩体的岩石学、锆石U-Pb年代学和全岩地球化学资料,以确定岩体的形成时代、岩石成因及其构造属性。正长花岗岩样品中岩浆锆石SHRIMP U-Pb加权平均年龄为(425.7±2.5) Ma(MSWD=1.07),属晚志留世,与金川地区出露的辉绿岩脉年龄相近。正长花岗岩低硅(SiO₂ 66.71%~70.05%),富碱(Na₂O+K₂O 10.00%~10.7%),K₂O/Na₂O比值为1.88~2.41,高全铁(FeO^T 1.79%~2.62%),低钛(TiO₂ 0.34%~0.52%),A/CNK=0.82~1.05。岩石学及化学成分显示其属于准铝质碱性系列A1型花岗岩,具有较高的锆石饱和温度(T_Zr=878~1 015 ℃);稀土元素含量高,ΣREE含量为374.4×10^-6~529.4×10^-6(平均428.7×10^-6),稀土元素配分曲线呈现轻稀土元素相对富集、重稀土相对亏损的右倾分布特征,(La/Yb)_N=28.07~41.28,具Eu负异常(δEu=0.53~0.66)。原始地幔标准化微量元素蛛网图显示Nb、Ta、Ti和P的亏损。岩石具有较高的Rb/Sr值(介于0.81~1.27之间,平均值为1)和Rb/Nb值(介于4.72~9.75之间,平均值为7.15),显示壳源岩浆的成分特征。结合区域地质背景及构造判别认为,金川正长花岗岩形成于上地壳长英质物质在高温条件下的部分熔融,同时代出露的辉绿岩脉与其组成的双峰式侵入岩形成于伸展的板内裂谷环境,与约426 Ma阿拉善地块和祁连-柴达木地块导致的俯冲板片断裂、折返以及软流圈地幔的上涌有关,金川地区“I6隐伏矿体”形成以后所经历的构造活动及热液成矿作用的叠加可能与该双峰式岩浆活动有关。  相似文献   

复合点坝侧积周期的成因分析:以密西西比河下游段为例^*          下载免费PDF全文

范洪军  王夏斌  胡光义  范廷恩  何明薇  陈飞 《古地理学报》2021,23(2):421-434

复合点坝侧积体定量成因分析是河流沉积学研究的难点之一。通过选取密西西比河下游段激光雷达数据,剖析复合点坝侧积体的内部特征,统计侧积体高程数据,发现其符合周期变化的特点。对高程数据进行傅里叶变换计算,得到复合点坝侧积周期,将侧积周期与河道规模进行拟合,两者符合线性关系,拟合度高。深入分析后,认为侧积周期受河流的季节性洪泛周期控制。研究结论为侧积体定量成因分析提供了理论依据。  相似文献   

大兴安岭漠河前哨林场侵入岩年代学、岩石地球化学特征及其地质意义     

陆胜  王可勇  赵焕利  相雷  刘阳  张志博 《吉林大学学报(地球科学版)》2021,51(1):126-140

前哨林场大地构造上位于大兴安岭北段额尔古纳地块北部的漠河前陆盆地边缘。本文研究了大兴安岭漠河前哨林场侵入岩的岩相学、年代学及岩石地球化学特征,探讨了研究区内侵入岩的形成时代、岩石成因及其构造环境。LA-ICP-MS锆石U-Pb定年结果表明,花岗岩形成于199.9~199.3 Ma、辉长岩形成于（201.8±2.6） Ma,即研究区内的花岗岩、辉长岩均形成于晚三叠世—早侏罗世。岩石地球化学研究表明：花岗岩的w（SiO₂）为63.22%~70.10%,w（Al₂O₃）为12.43%~14.36%,里特曼指数（σ）为0.74~1.65,属高钾钙碱性系列岩石,具有较低的Mg^#值（平均值为39.43）,w（TFeO）为2.80%~4.41%,w（CaO）为1.47%~3.38%,轻重稀土分馏明显,富集轻稀土,亏损重稀土,δEu为0.48~0.84,富集Rb、Ta、K、La、Nd、Zr、Ti等元素,相对亏损Th、U、Sr、P、Eu等元素;辉长岩的w（SiO₂）为51.42%~51.98%,w（Al₂O₃）为17.24%~17.73%,里特曼指数（σ）为3.00~3.53,属高钾钙碱性系列岩石,具有较高的Mg^#值（平均值为51.07）,w（TFeO）为9.06%~9.14%,w（CaO）为5.81%~6.69%,重稀土分馏不明显,δEu为0.86~0.98,富集Rb、Ta、Nb、Nd等元素,相对亏损Th、U、P、Eu等元素。上述岩石地球化学特征表明,花岗岩为辉长岩结晶分异的产物,原始岩浆起源于地幔,并受地壳物质的混染改造。研究区侵入岩形成于造山阶段挤压环境,是蒙古—鄂霍茨克洋俯冲碰撞的产物。  相似文献   

赤峰—开源断裂在赤峰西部地段的构造形迹及其演化特征     

马国祥 《世界地质》2018,37(3):791-803

为研究赤峰—开源断裂在赤峰西部地段的性质,笔者在1∶5万朝阳地幅、姜家营子幅区调工作中,利用岩石学、岩石地球化学、LA—ICP—MS锆石U—Pb测年等方法,对构造控制的多期次侵入岩进行构造环境研究。结果表明,晚泥盆世二长花岗岩年龄为382. 8±2. 1 Ma,形成于同碰撞挤压环境;晚泥盆世超基性岩年龄为378. 4±3. 2 Ma,形成于碰撞后裂谷拉张环境;早二叠世二长花岗岩、石英闪长岩年龄分别为280. 1±1. 5 Ma、275. 7±1. 8 Ma,形成于同碰撞挤压环境;晚三叠世、早白垩世花岗斑岩年龄分别为206±25 Ma和128. 8±1. 3 Ma,形成于非造山伸展拉张环境。构造带上带状构造的野外地质调查发现构造带经历了3期韧性和1期脆性变形,分别为晚泥盆世至晚石炭世北东东向右行正斜滑韧脆性剪切(构造内花岗斑岩脉年龄374. 2±2. 6 Ma),早二叠世北东东向左行正斜滑韧性剪切(构造内花岗斑岩脉年龄270. 3±1. 7 Ma),晚三叠世北西西向左行正斜滑韧脆性剪切(构造内辉长岩年龄247. 53±7. 4 Ma)和中侏罗世至早白垩世北东和北西向脆性断裂。显示赤峰—开源断裂在赤峰西部地段表现为多期次挤压、间歇伸展,并以挤压造山为主的构造-岩浆岩带。  相似文献   

井地电法不同供电方法对地表电场的影响     

沈明燮  杜立志  吕守航 《世界地质》2018,37(2):602-607

为研究线源和点源供电方法的差异,在实验室利用水槽建立物理模型。由于水相对于油层而言呈低阻特征,因此试验中用铜板模拟低阻体,用铜棒模拟线电源供电,铜柱模拟点电源供电,改变低阻体与供电电源的相对位置,测试表面电位的空间分布,从而分析驱油介质(水)的空间分布。实验结果表明,不同的电源供电方法可以表现出不同的电场特性,线电源供电方法对电场的影响较大,对低阻体的识别效果较差,而点电源供电方法用于低阻体的识别和监测效果较好。  相似文献   

Cretaceous A-type volcanic–intrusive rocks and simultaneous mafic rocks along the Gan-Hang Tectonic Belt,Southeast China: petrogenesis and implications for the transition of crust–mantle interaction     

Hong-Zuo Wang  Pei-Rong Chen  Kai-Xing Wang  Hong-Fei Ling  Jun-Qi Wu  Jiang-Wei Tang 《International Geology Review》2018,60(11-14):1684-1706

ABSTRACT

Abundant evidence points to the Cretaceous crust–mantle interaction and plate subduction in the Gan-Hang Tectonic Belt (GHTB), southeastern China, but the evolutionary process remains poorly constrained. Here we conduct a comprehensive study on Daqiaowu granitic porphyry and diabase dikes in the eastern GHTB, in conjunction with previous studies on simultaneous felsic and mafic rocks along the GHTB, to demonstrate their petrogenesis and geodynamic evolutionary process. The Daqiaowu granitic porphyry (125 Ma), as well as the coeval granitic rocks, exhibits high zircon saturation temperatures, alkalis, 10⁴*Ga/Al ratios, and Zr + Nb + Ce + Y contents, concluding a distinctive belt of the Early Cretaceous (~137–125 Ma) A-type volcanic–intrusive rocks in the GHTB. Their ε_Nd(t) and zircon ε_Hf(t) values gradually increased through time from approximately ?9.0 to ?1.0 and ?10.0 to +4.0, respectively, implying increasing contribution of mantle-derived components to their formation, and hence progressively intensified crust–mantle interaction in an intra-arc rift environment (a geodynamic transition stage from continental arc to back-arc) during the Early Cretaceous. This plausibility is further supported by the Early Cretaceous Daqiaowu diabase dikes and coeval mafic rocks which exhibit arc-like magmatic signatures and were derived from mantle wedge. In contrast, the Late Cretaceous mafic rocks show ocean island basalt-like geochemical characteristics, reflecting a depleted asthenosphere mantle source. This discrepancy of mantle sources concludes that the geodynamic setting in the GHTB may have basically transferred to back-arc regime in the Late Cretaceous. Thus, the Cretaceous geodynamic evolutionary process in the GHTB can be defined as the Early Cretaceous gradually intensified crust–mantle interaction in a geodynamic transition stage (from continental arc to back-arc extension) and the Late Cretaceous back-arc extensional setting.  相似文献